The invention relates to a method and a device for pressure-controllable handling of a fluid. The device makes possible, in particular, even and steadied, in particular pressure-controlled, injection of a fluid, which can be a liquid or a gas. The device can also be used in different ways as a probe for inserting cannulas and when placing catheters. In particular, the invention relates to the further development of a syringe for medical purposes. A preferred field of application is anaesthesia.